Systems for restraining vehicle occupants during front and side impacts are known in the art. Each vehicle side seat location having a side restraint includes an associated actuatable side airbag assembly. A controller is connected to the side airbag assembly. The controller controls actuation of the airbag in response to signals provided from crash sensors. Typically, each side airbag assembly has an associated side crash sensor. One known side crash sensor for a side restraint system is a "crush sensor" having a contact switch which closes upon crushing of a vehicle side assembly, e.g., a door, during a side impact crash event. Other side restraint systems use an accelerometer as a crash sensor. One concern regarding use of an accelerometer as a side crash sensor is the ability to discriminate between a side crash event and a door slam event.
Known frontal restraint systems include two crash sensors. One of the crash sensors functions as a "primary" crash sensor and is used for crash discrimination purposes. This primary crash sensor is referred to in the art as a "discrimination" crash sensor. The other crash sensor is a "secondary" crash sensor and is referred to in the art as a "safing" crash sensor. Notwithstanding the names given these crash sensors, actuation of the restraint system requires detection of a deployment crash condition by both the discrimination crash sensor and its associated safing crash sensor.